Healthy, HIV-negative subjects are being recruited for investigational studies of vaccines to prevent infectious diseases (other than HIV) through protocol VRC-300 (NIH 03-I-0285). In FY 04 the VRC completed recruitment of 27 subjects for a clinical trial of an investigational Ebola vaccine trial. The screening study was used to determine if the subject met eligibility requirements for participation in Phase I trials of preventative vaccines. Educational materials on vaccines were reviewed with and provided to subjects before enrollment into the vaccine study. The Ebola vaccine study is included in the VRC Biodefense mission.